Maximum Heart Rate formulas

[SquawMan]

thought this was an interesting article.....in practice, I've found what he says to be true



MAXIMUM HEART RATE FORMULA IS WRONG

Gabe Mirkin, M.D.

Many of the standard tests used to measure heart function are based on a nonsensical MAXIMUM HEART RATE formula, that predicts the fastest your heart can beat and still pump blood through your body. Although this formula is the golden standard used today, it is not based on science. In 1970, a good friend, Sam Fox, was the director of the United States Public Health Service Program to Prevent heart disease. He is one of the most respected heart specialists in the world. He and a young researcher named William Haskell were flying to a meeting. They put together several studies comparing maximum heart rate and age. Sam Fox took out a pencil and plotted a graph of age verses maximum heart rate and said it looks like maximum heart rate is equal to 220 minus a person's age. For the last 30 years, this formula has been taught in physical education and heart function course and has been used to test heart function and athletic fitness. In the 1960s, Sam Fox was very helpful to me when I was competing, planning and setting up running programs, but the whole concept of maximum heart rate and the formula that it is equal to 220 minus your age is ridiculous.

The formula is wrong because your legs drive your heart. Your heart does not drive your legs. Maximum heart rate depends on the strength of your legs, not the strength of your heart. When you contract your leg muscles, they squeeze against the blood vessels near them to pump blood from your leg veins toward your heart. When your leg muscle relax, your leg veins fill with blood. So your leg muscles pump increased amounts of blood toward your heart. This increased blood fills the heart and causes your heart to be faster and with more force. This is called the Bainbridge reflex that doctors are taught in their first year of medical school. The stronger your legs are, the more blood they can pump, which causes your heart to beat faster. Since I race at my maximum speed most weekends on my bicycle, my legs are very strong and can pump blood forcibly to my heart. The formula, 220 minus age, claims that I can get my heart rate only up to 220 minus 66 or 154. I am 66 years old and I can easily get my heart rate above 210 beats a minute because I am in shape. An out-of-shape 20 year may have maximum heart rate of only 120.

A pencil mark plotted on a graph during an airplane flight more than 30 years ago has been the accepted formula for maximum heart rate for more than 30 years and the medical community has accepted false dogma, based on no research, for more than 30 years.

[Plakespear]

The 220-age formula is only a guideline. This has been known for a long time. There are better ways to determine your actual Max HR

[Laps]

That would make sense, considering the better shape you are in, the lower your heart rate is. I wonder why it has taken 30 years to figure this out.....

[lph]

That would make sense, considering the better shape you are in, the lower your heart rate is. I wonder why it has taken 30 years to figure this out.....

but doesn't that contradict what the guy is trying to say. he is saying that the better shape you are in, the stronger your legs are, the more forcibly the muscle contracts, then there is more blood return to your heart and your heart beats faster.

I am not expert, but i don't ever remember being taught that the amount of blood returning to your heart determines your heart rate.

Not to mention, that amount of blood returned to your heart, is entirely dependent on how much gets to your legs by your arteries, the amount of which is dependent on how much blood your muscles require and is pumped by your heart to get there. Muscles which have been trained require less blood flow to clear the lactic acid build up and therefore your heart rate is slower.

perfect example would be bjorn borg, or Indurain. resting heart rate in the 30's to 40's and when they were playing/biking i don't think their heart ever approached their maximum.

I think the guy above (and me) are way oversimplifying the whole thing. Although the 220 minus age is also oversimplifying it as well.

[Laps]

I was thinking that the better shape you are in, the more relaxed your legs would be when exercising, therefore, the lower your heart rate is. But, I agree that this is very simplistic, and there are so many other things to consider, like the rate at which oxygen is processed and the how that affects heart rate, etc.

[Morris Buttermaker]

The article makes it sound like the only exercise you would have to do to have a strong and healthy heart would be squats, because the stronger your legs, the stronger your heart.

I wonder if at the end of the article he stated that he wasn't really a doctor, but he stayed at a Holiday Inn the night before.

[Viva]

The Brainbridge Reflex is a response to increased cardiac load. It was first demonstrated in dogs by simple venous infusion. In other words, increase the volume of stuff going to the heart and the heart responds by beating faster to accomodate that extra volume.

The Bainbridge reflex is controversial because it's not always reproducible. In dogs, intravenous infusions can either initiate reflex tachycardia or, sometimes bradycardia. Also, it is not clear that there is a bono fide Bainbridge reflex in humans. Almost everything we know about it come from studies using dogs.

While increased volume load to the heart from running certainly affects heart rate (HR), stroke volume (SV), etc., I don't think that there's any convincing evidence that this is the sole determinant. There may also be an opposing baroreflex that serves to maintain arterial pressure within a certain range.

lph, the better conditioned a person is, the lower the resting HR. This is because the heart beats more efficiently and left ventricular growth (ventricular hypertrophy) results in a stronger contraction and greater SV. The conditioned heart will also be able to maintain a higher max. HR over time. I don't know that a normal conditioned person is going to have a max HR that's significantly greater than 220 - age.

[SkiingBear]

I seriously doubt that this guy is exercising at a heartrate of 210 bpm...at 66 years old, he's probably more likely having a mild heart attack.

Through my experience with max HR, I've found that my max to be 193. I'm 28 years old, and if you do the math 220-28=192...so yeah, the general rule seems to be pretty close. I'm basing all of these numbers on the data I've obtained from my Polar HR monitor, and I have well over 100 exercise files supporting them. Is 193 truly my "maximum" heartrate? I don't know, but I do know that 193 is the fastest I've been able to get it to beat while exercising strenuously.

The whole idea of the legs actually pumping blood up to the heart is ridiculous. When the muscles in your legs contract and constrict the blood vessels, it's going to increase the pressure in both directions. This article makes it sound like there are void spaces forming in your veins and the contraction of the leg muscles helps to push blood to fill them. More accurately, the strength of your muscles during exercise affects your blood pressure.

Because the Bainbridge Reflex is not a reproducible test, I'm going to put little faith in it right now. It sounds a lot like people hypothesizing something that they don't understand. "Hey, this happens some of the time...maybe it's a hard and fast rule!"

[bklyn]

Thanks - I learned much from this thread.

So all that adipose tissue I'm carrying; concentrated around my gluteus' minimus, medius, maximus, rectus abdominis and biceps femori is the reason my maximum heart rate is so high.

This is how Iive beat out the other girls in the club when I 'drop it like it's hot'.

[lph]

Yeah, all you said makes perfect sense Viva and supports the idea that this MD has oversimplified ALL the variables that go into HR.

skiingbear, muscular contraction in your legs does result in increased venous return to your heart. And yes, increased blood pressure is in part due to increased contraction of your muscles as the arteries need the pressure to stay open and flowing during exercise (again, this one variable of many and again it is oversimplified).

this docs little article is quasi-scientific at best.

[Laps]

I wonder what Bklyntrayc's avatar would do for the DR.'s heart rate.